The present invention relates to a method of creating a barrier to protect wood materials used for construction and wooden structures from humidity and/or biological attacks, and more particularly against the effects of fungi growth or infestation by insects such as termites.
All types of wooden structures, and in particular wooden houses, are subject to being exposed to the action of humidity in the atmosphere and, depending on location, to dampness or water seepage. This creates an ideal atmosphere for growth of fungi such as mildew and the like. When wooden structures are attacked by wood-decaying fungi, they can be seriously damaged, especially when the foundation that supports the structure and stability of the house is attacked. The deterioration of wooden structures by the action of humidity and by the biological attacks are inter-related, because wood-decaying fungi and termites thrive and proliferate under humid conditions, such as are found under the floors of homes where water evaporates from the ground surface.
It is, therefore, very important to protect the wood materials employed for house construction and wooden houses and structures from the action of humidity, fungi, insects and other biological attacks in one convenient procedure.
Heretofore, proposals have been made to prevent the action of humidity from the ground surface and to control the biological attacks. For example, it has been suggested to cover the ground surface with polyethylene sheets in order to cut off humidity therefrom. Likewise, it has been proposed to cover the ground surface with sheets, called "termite-controlling sheets", in order to attain various objects, such as prevention of exposure to humidity, for wood preservation and for termite control at the same time.
However, these methods have occasioned a number of drawbacks. For instance, it is a labor intensive effort to spread sheets on a ground surface in a satisfactory manner. It is necessary to first cut sheets to adapt them to irregularly shaped foundations; in order to reduce the tendency to cause gaps thereby leading to imperfect prevention against humidity and moisture.
It has also been proposed in the past to spray a variety of synthetic resin containing liquid preparations, which can contain active ingredients such as termite-controlling agents and/or wood-preservative agents, on the ground surface under the wooden structure. However these methods also were not totally successful. For example, the synthetic resin liquid preparations tend to penetrate into the soil before a dried film is formed on the soil surface. Hence, a much larger quantity of the liquid is required in order to attain the desired objects of adequate protection. Further, as the soil surface is usually uneven, mounded parts may not be sufficiently treated with the liquid and, as the result, a uniform film may not be formed on the whole surface of the soil. This results in imperfect moisture and insect resistance and poor wood-preservative effects.